I know this isn't probably what you want to hear, but use this as a motivation to be better. From what I can tell from your post, you are educated and have a great sense of higher thinking, even though you've given in to the internal self-deprecation that points out every mistake you make or every missed opportunity. I know it's hard as hell to talk yourself off that ledge into that pit every single day, but always remember that every victory you have, no matter how small, is a step toward building your perceived self worth. This is coming from someone who went from dropping a hair dryer in the tub with him to having a career he loves and in a relationship with someone he loves in a span of a few years. Even then, I'm still working through depression and anxiety, but I'm here to tell you that no matter how insurmountable your obstacles, you have the education, the intelligence, and the willpower to beat those obstacles... because if a small victory can get you rich the day, imagine what a long-term larger victory can give you. Hang in there! You have everything you need within you to beat these negative feelings.